In general, a mobile communication system was developed to provide voice services while guaranteeing activity of users. However, the mobile communication systems have extended their fields to the data providing service beyond the voice communication providing service and have now developed up to a level at which they can provide a high speed data service. In spite of such a development, current mobile communication systems are undergoing a deficiency of resources and users of current mobile communication systems require a service of a higher speed.
Long Term Evolution-Advanced (LTE-A) in the 3rd Generation Partnership Project (3GPP) is a technology implementing a high speed packet-based communication having a transmission speed of a maximum of 1 Gbps. The LTE-A employs a scheme which increases the number of cells accessible by a mobile station while allowing feedbacks occurring in respective cells to be transmitted in only a Primary cell (P cell or Pcell). Further, in the LTE-A, all the cells accessible by a mobile station have the same duplex structure. Therefore, all the cells may have a Frequency Division Duplex (FDD) structure or may have a Time Division Duplex (TDD) structure. The TDD structure may be a static TDD structure in which a UL-DL configuration is maintained or a dynamic TDD structure in which the UL-DL configuration is changed by system information, a higher layer signal, or a downlink common control channel.
If one cell controlled by a base station has an FDD structure and a single frequency band is added, it is easy to apply a TDD structure to the single frequency band. It is because two different frequency bands are required for the downlink and the uplink, respectively, in order to operate an FDD structure.
Therefore, there is a necessity for a scheme for transmitting a control channel for data transmitted from a plurality of cells when the cells have different duplex schemes due to the addition of limited frequency bands as described above or other reasons. In relation to an uplink control channel for downlink data, when feedbacks for a plurality of cells are allowed to be transmitted only in a Pcell, a mobile station requires a technology for transmitting feedbacks of cells having different frame structures in Pcell. Further, in relation to a downlink control channel for uplink data, there is a necessity for a technology in which a base station can schedule uplink data to a mobile station and transmits a downlink control channel for the uplink data to the mobile station.